90 SEALS AND WHALES OF THE BRITISH SEAS. 



mouth, of a white colour. The upper part of the head, called the " case," 

 contains the "spermaceti," which upon the death of the animal granulates 

 into a yellowish substance. Beale says that a large Whale not unfrequently 

 contains a ton of spermaceti. Beneath the "case" is situated the "junk," 

 which consists of a dense cellular mass, containing oil and spermaceti. The 

 blubber is about fourteen inches thick on the breast, and in most other parts 

 of the body from eight to eleven inches. By the whalers this covering is 

 called the "blanket." With regard to the apparently ungainly head of the 

 Sperm Whale, Beale remarks as follows : — " One of the peculiarities of the 



Fig. 20. Skull of Sperm Whale. 



Sperm Whale, which strikes at first sight every beholder, is the apparently 

 disproportionate and unwieldy bulk of the head ; but this peculiarity, instead 

 of being, as might be supposed, an impediment to the freedom of the animal's 

 motion in its native element, is, in fact, on the contrary, in some respects, very 

 conducive to its lightness and agility, if such a term can with propriety be 

 applied to such an enormous creature ; for a great part of the bulk of the 

 head -is made up of a thin membranous case, containing, during life, a thin 

 oil, of much less specific gravity than water, below which is again the junk, 

 which, although heavier than the spermaceti, is still lighter than the element 



